*{
    box-sizing: border-box;
}
body{
    background-color: #296ca8;
    color: #fff;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin: 0;
    min-height: 100vh;
    /* 给加载动画留出一个空间 */
    padding-bottom: 100px;
}
h1{
    margin-bottom: 0;
    text-align: center;
}
/* 搜索区域 */
.filter-container{
    margin-top: 20px;
    width: 80vw;
    max-width: 800px;
}
/* 输入框 */
.filter{
    width: 100%;
    padding: 12px;
    font-size: 16px;
}
.post{
    /* 给文章编号进行定位参考的 */
 position: relative;
 background-color: #4992d3;
 width: 80vw;
 max-width: 800px;
 margin: 40px 0;
 padding: 20px;
 border-radius: 5px;
 box-shadow: 0 2px 4px rgba(0,0,0,.6);
}
.number{
    position: absolute;
    top: -15px;
    left: -15px;
    background-color: #fff;
    color:  #4992d3;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 7px 10px;
}
/* 加载动画 */
.loader{
  opacity: 0;
  display: flex;  
}
.loader.show{
    opacity: 1;
}
.circle{
    background-color: #fff;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    margin: 5px;
    animation: bounce 0.5s ease-in infinite;
}
.circle:nth-of-type(2){
    animation-delay: 0.1s;
}
.circle:nth-of-type(3){
    animation-delay: 0.3s;
}
@keyframes bounce{
    0%,100%{
        transform: translateY(0);
    }
    50%{
        transform: translateY(-10px);
    }
}
